Docs: Keep the module index clean (#46155)

A lot of modules have a short_description with a trailing dot even
though we don't want trailing dots in the index. This change removes
it when creating the document index.

lib/ansible/parsing/plugin_docs.py

@@ -103,6 +103,7 @@ def read_docstub(filename):
             capturing = True
             doc_stub.append(line)
 
-    data = AnsibleLoader(r"".join(doc_stub), file_name=filename).get_single_data()
+    short_description = r''.join(doc_stub).strip().rstrip('.')
+    data = AnsibleLoader(short_description, file_name=filename).get_single_data()
 
     return data